Science

Demonstration of a link between COVID-19 and a rare neurological pathology

More than a year after the first cases of COVID-19, and several months after the deployment of vaccines around the world, scientists continue to study the effects of the coronavirus SARS-CoV-2 (and its variants) on the organization. Recently, a team of researchers found a link between COVID-19 and the occurrence of acute transverse myelitis, a rare neurological complication of the disease causing inflammation of the spinal cord.

Acute transverse myelitis (ATM) – an inflammation of the spinal cord that can cause pain, paralysis, and sensory problems – has been identified in 43 cases of COVID-19 in adults in 21 countries, with patients aged 21 to 73 years old, as well as 3 children aged 3 to 14 years old. The study brings together previous research and case reports, and according to the team, the data is sufficient to warrant further investigation. In any given year, the incidence of TMJ is estimated to be only 1.34 to 4.6 cases per million people.

A neurological complication less rare than expected

In contrast, over a 10-month period, the incidence of TMJ in patients with COVID-19 alone ended up being around 0.5 cases per million, setting off red flags for researchers. ” We found TMJ to be an unexpected neurological complication of COVID-19. Most cases (68%) showed a latency of 10 days to 6 weeks which may indicate post-infectious neurological complications mediated by the host’s response to the virus », Write the authors.

The new research adds to what we already know about COVID-19 and neurological complications: The disease has been linked to many problems with the nervous system, such as a lingering effect of brain fog. In these 43 cases, spinal cord injury was found to lead to quadriplegia and paraplegia, with other associated problems including loss of bladder control. The research was undertaken after the discovery of a case in Panama.

MRI images showing inflammation of the spinal cord (arrows) in TMJ. © Gustavo C. Román et al. 2021

Other cases were then collected from the scientific literature published between March 2020 and January 2021. ” This study confirms that TMJ is not uncommon as a neurological complication associated with COVID-19 worldwide, possibly responsible for 1.2% of all neurological complications caused by this coronavirus », Concludes the team.

Better understand the immune mechanisms involved

Since TMJ is known to be an immune-mediated disease (which means the main cause is unclear, but there is involvement of our immune system and inflammatory processes in the body), the researchers indicate that there are potential immune mechanisms that could explain how SARS-CoV-2 can lead to TMJ.

In addition, the team also notes that three cases of ATM have occurred during the AstraZeneca vaccine trials. Although each has been studied, the researchers note in this study that they could provide a clue to the immune mechanisms involved. ” The pathogenesis of TMJ remains unknown, but it is conceivable that SARS-CoV-2 antigens – possibly also present in the AZD1222 anti-COVID-19 vaccine or its adjuvant of chimpanzee adenovirus – could induce immune mechanisms leading to myelitis “.

Further studies should help find more answers and the antigens involved, but it is a reminder that we are still a long way from understanding all that COVID-19 entails, even as vaccines are rolled out across the world. Previous research has identified pregnancy-related complications in people who contract COVID-19, and there is also the lingering problem of long-term COVID.

Sources: Frontiers in Immunology

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